Device and method for removing sealing material

ABSTRACT

Disclosed is a device for removing sealing material on components of an aircraft having a drive unit and a tool connected to the drive unit. The drive unit can, for example, be realized with the aid of an electric motor and an eccentric. Accordingly, the tool, which can be actuated by hand, is set in a quickly oscillating to and fro movement parallel to a longitudinal axis of the tool by means of the drive unit, as a result of which the force to be applied by a user in order to lift off or tear away the sealing material from a joint is substantially reduced. An underside  22  of the tool forms with a wedge face a sharp cutting edge for detaching the slug of the sealing material from the base of the joint. The wedge face can be flat, concave or arbitrarily generally curved in one or two spatial dimensions. Damage to the surface of the component, which can for example in the case of plated aluminum alloy sheets, lead to substantial consequential damage such as for example, to fatigue cracks, is avoided as a consequence of the material of the tool being softer by comparison with the material of the component to be processed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of German Patent Application No. 10 2006 052 508.6, filed Nov. 6, 2006, the entire disclosure of which is herein incorporated by reference.

FIELD OF THE INVENTION

The invention relates to a device for removing sealing material on components of an aircraft, in particular an airplane, having a drive unit and a tool connected to the drive unit.

BACKGROUND OF THE INVENTION

In modern airplane construction, the fuselage cells of the airplane are generally formed from a multiplicity of fuselage sections (“fuselage barrels”) which are arranged one behind another and interconnected. The fuselage sections are, in turn, formed with the aid of a number of interconnected fuselage shells, for example an upper shell, a lower shell and with the aid of side shells. The fuselage shells are, in turn, produced of aluminum alloy sheets connected by riveting. Wings, vertical tails and the elevator of an airplane are joined together in the same way from structural components.

In general, the structural components are currently still riveted together and/or screwed to one another.

The seams or joints produced between the components are sealed to one another hermetically by means of known elastic, heat resistant and strongly adhesive sealing materials or sealing agents.

In general, the airplane is repainted after eight to twelve operational years. To this end, the sealing material must be removed again from all grooves and joints in order to ensure acceptable appliance of paint.

The devices used so far for detaching the sealing materials are based on a manually mechanical action on the sealing seam. The scraping and cutting tools particularly used for this purpose have blades partially formed with metallic materials.

When applying the previously known devices for removing sealing material between the structural components in the course of preparatory painting work, there is always the risk that the surfaces of the components, which are often produced with the aid of high-alloy aluminum sheets, are impaired by the scraping and cutting tools (so-called “scribe marks”), the result of which is, firstly, that the corrosion properties can be adversely affected. Secondly, mechanical damage to the fuselage cell skin which in many instances is formed with the aid of high strength, plated aluminum alloy sheets can promote the production of fatigue fractures. Moreover, the manual removal of the sealing materials from the component joints by means of the previously known devices is extremely time consuming and also requires a high degree of experience.

SUMMARY OF THE INVENTION

It is an object of the invention to avoid the previously described disadvantages of the known devices.

Accordingly, a device for removing sealing material on components of an aircraft is disclosed, which comprises a drive unit and a tool connected to the drive unit, wherein the tool can be caused by the drive unit to execute oscillating movements parallel to a longitudinal axis of the tool in order to facilitate the removal of the sealing material.

Owing to the fact that the drive unit can be used to cause the tool to execute oscillating movements parallel to a longitudinal axis of the tool, in order to facilitate the removal of the sealing material, the inventive device can be used to detach the sealing material quickly and easily from the joints between the structural components. The drive unit in this case ensures relatively easy removal of the sealing material without excessive use of force by the user.

According to one embodiment, in the region of the processing section the tool has a width which corresponds approximately to a width of a joint between the components, from which the sealing material is to be removed.

It is thereby ensured that the sealing material is also removed from the edge regions of the joint and, particularly, of the base of the joint in a way that is largely free from remnants. The width of the processing section is preferably selected to be slightly smaller than the width of the joint in order to avoid jamming of the tool in the joint.

According to a further embodiment, it is provided that the tool has a cross-sectional geometry which corresponds approximately to a cross-sectional geometry of a joint.

It is possible by means of this refinement to detach or pare away the sealing material even from joints which have a shape deviating from a rectangular or square cross-sectional geometry. In the case of a joint having a base of the joint which is, for example, of semicircular shape, the cutting edge of the tool is preferably adapted approximately to this curve. Owing to individual adaptation of the cutting edge geometry, it is possible to remove the sealing material virtually free from remnants and with an acceptable outlay, even in the case of complex cross-sectional geometries.

In accordance with a further embodiment of the invention, the tool is formed with a material which is softer by comparison with the components, in particular with a polycarbonate or in particular with a hardwood. As a consequence of the at least slightly lower material hardness of the tool by comparison with the components to be processed, damage in the surface region of the components is largely avoided when detaching the sealing material from the joints. There is no need here to form the tool completely from a plastic material such as, for example, a polycarbonate or from a hardwood.

In an alternative embodiment, only the processing section of the tool is produced with the aid of the known materials. The tool shank pointing away from the processing section and which is clamped in the tool holder of the device can, by contrast, be produced with the aid of a conventional steel, a stainless steel or the like. It is possible here to provide a refinement in the case of which the processing section can be removed from the tool shank, for example in the case of wear, and be replaced by a new processing section having a cutting edge which is still sharp.

Moreover, the tool shank of the tool can also be formed from a fibre-reinforced plastic material, in particular a carbon fibre-reinforced epoxy resin, in order to further increase the flexibility of the tool. The tool shank, which in this case is a resiliently elastic design, can be excited to natural vibrations by the oscillating movements, the result of which is that the removal action of the tool is further increased.

Furthermore, instead of polycarbonate or hardwood it is possible to use other materials which have a lesser hardness by comparison with the aluminum alloy of the components.

Another embodiment of the device provides that the processing section is substantially a wedge-shaped design, a wedge face enclosing an angle α of between 20° and 60° with an underside of the tool while forming a cutting edge.

In conjunction with the movements, oscillating parallel to the longitudinal axis of the tool in an axial direction, of the tool, said angular range of the tool permits the sealing material to be removed from the joint with the expenditure of little force and at the same time virtually without remnants.

The wedge surface of the tool, which is flat in one embodiment is designed to be inclined by said angular amounts with reference to the longitudinal axis of the tool or the underside of the tool. Alternatively, the wedge face can be designed to be curved in one or two dimensions, particularly in the case of joints having a cross-sectional geometry deviating from a quadrangular shape. Furthermore, it is possible for the wedge face to be of concave design in order to facilitate the slug of sealing material detached from the joint in running out and away over the tool.

Furthermore, the object is also achieved by a method for removing sealing material on components of an aircraft by the above-described device, wherein the underside of the tool is guided inside a joint underneath the sealing material at a working angle β, with respect to a surface of the component.

By virtue of the fact that an underside of the tool is guided inside the joint underneath the sealing material at a working angle β, in particular at a working angle β of between 0° and 20°, with reference to a surface of the component, the user applies relatively less force when using the inventive device, while simultaneously avoiding damaging the component surface of the processed component.

Moreover, the claimed mode of procedure enables the sealing material to be removed from the joints virtually without remnants, that is to say completely.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic view of the inventive device,

FIG. 2 shows an enlarged perspective view of the tool,

FIG. 3 shows a side view of the mode of procedure when removing sealing material from a joint by means of the device, and

FIGS. 4-7 show different shapes of joint which can be removed by means of the device.

In the drawing, the same structural elements respectively have the same reference numerals.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a simplified diagrammatic illustration of the inventive device.

The device 1 comprises a drive unit 2 and a tool 3.

By means of the drive unit 2, the tool 3 is caused to execute oscillating movements parallel to a longitudinal axis 4 of the tool in the direction of the double arrow 5. The tool 3 here completes an oscillating movement with a stroke travel 6.

In the exemplary embodiment of FIG. 1 which is shown, the drive unit 2 comprises an electric motor 7, an eccentric 8, an eccentric rod 9 and a ram 10 which is held displaceably parallel to the axis of the tool in a thrust bearing 11. The thrust bearing 11 can, for example, be formed with the aid of a thrust ball bearing, a roller bearing bush or the like. The ram 10 is connected to a tool holder 12. A tool 3 is preferably held in the tool holder 12 in a fashion so that it can be removed and reclamped. As a result, it is easy for a user to be able to replace the tool 3. The tool 3 is, for example, clamped in the tool holder 12 by means of a screw fitting 14.

As a consequence of the rotary movement of the electric motor 7 in the direction of the arrow 15, the eccentric 8 is set rotating in an opposite direction of rotation in the direction of the arrow 16 and so, owing to the connection of eccentric rod 9 and ram 10, the tool 3 is caused to execute an oscillating pushing movement parallel to the longitudinal axis 4 of the tool with the stroke travel 6 in the direction of the double arrow 5. The impulsive to and fro movement of the tool 3 penetrates the sealing material of the joint such that said material can be removed relatively easily from the joint. The eccentric rod 9 can be formed on the eccentric such that it can be displaced on the eccentric in a radial direction continuously or latchably in order to enable the stroke travel 6 to be adjusted or adapted. Moreover, the frequency of the linearly oscillating movement of the tool 3 can be set continuously via a speed of the electric motor 7 by means of a preferably electronic control and regulation device which is not illustrated.

In a deviation from the exemplary embodiment described, the drive unit 2 can be implemented in other mechanically and/or electromagnetically acting drive units. For example, the ram 10 with the tool 3 fixed thereon can be moved directly in an oscillating fashion in an axial direction by a strong electromagnet.

Furthermore, the drive of the tool 3 can be performed by pneumatic and/or hydraulic devices.

The tool 3 has a processing section 17 which is directed away from the tool shaft 13. The processing section 17 has a cutting edge 18 and a wedge face 19 which is flat in the exemplary embodiment shown in FIG. 1. The cutting edge 18, which is preferably ground sharp, serves for scraping away or detaching the sealing material from the joint. In the exemplary embodiment shown, the wedge face 19 encloses an angle α of approximately 45° with the longitudinal axis 4 of the tool or an underside of the tool. In order to attain optimum operating results with the inventive device, the angle α between the longitudinal axis 4 of the tool and the wedge face 19 is preferably between 30° and 45°.

The tool 3 is formed of a material which is less hard than the components or structural components to be processed. This prevents the mechanical integrity of the surface of the components to be processed (so called “scribe marks”) from being impaired as a consequence of the use of the inventive device. The tool 3 is preferably formed with the aid of a plastic material, in particular with the aid of a polycarbonate, a polyamide, a polyethylene terephthalate (PET) or with the aid of a hardwood such as, for example, beech, oak or ash. In a particular embodiment, only the processing section 17 is formed with the softer material, while the tool shank 13 is made of conventional steel or stainless steel.

In a further alternative embodiment, which is indicated in the drawing by the vertical, dashed line on the tool 3, the tool shaft 13 is designed such that it can be separated from and connected to the processing section 17 (“wearing section”). Consequently, in case of need it is possible, for example, for a processing section 17 which has been blunted as a consequence of relatively long use to be replaced by a new processing section 17 with a sharply ground cutting edge 18.

The device is preferably designed as a handheld device which can be guided by a user and has a weight of less than 4 kg, in particular of less than 1 kg.

FIG. 2 shows an enlarged perspective view of the tool.

The tool 3 comprises the processing section 17 with the obliquely set or inclined wedge face 19, as well as the cutting edge 18. Located in the region of the tool shaft 13 is a fastening bore 20 to which the fastening screw 14 can be inserted in order to fasten the tool 3 in the tool holder 12. The angle α between the wedge face 19 and the longitudinal axis 4 of the tool is preferably between 30° and 45°. A width 21 of the cutting edge 18 of the tool 3 corresponds substantially to the width of a joint from which the sealing material is to be cleared out. In order to avoid jamming of the tool 3 in the joint to be processed, the width 21 of the tool 3 is preferably selected to be slightly smaller than the joint width. The obliquely set wedge face 19 forms the cutting edge 18 together with an underside 22 of the tool. Here, the wedge face 19 and the longitudinal axis 4 of the tool or the underside of the tool enclose an angle α in a range of between 30° and 45°.

A height or thickness of the tool 3 is selected so as to avoid excessively strong sagging, yet, on the other hand, sufficient elasticity obtains.

The cutting edge 18 is designed with a straight line in the case of joints having a substantially quadrangular cross sectional geometry. In the case of a joint having a cross sectional geometry deviating therefrom, for example in the case of a joint with a base which has a substantially semicircular cross section, the cutting edge is designed for this purpose in a correspondingly semicircular or arcuate fashion. In this case, the geometrical shape of the wedge face 19 deviates from that of a plane and corresponds, for example, to a face curved in at least one spatial direction. Furthermore, it is possible in a deviation from the illustration of FIG. 2 for the wedge face to be designed with a concave curve (face curved in one dimension).

FIG. 3 illustrates diagrammatically the use of the inventive device in removing sealing material from a component joint to be processed.

A slug 24 to be removed by means of the device is located in a joint 23 having a cross sectional geometry which is substantially quadrangular in the exemplary embodiment shown. The slug 24 is formed with the aid of a commercially available, elastic and strongly adhesive sealing material 25 (“sealant”) such as, for example, polyurethane, silicone, acrylic or the like. In order to peel off or detach the slug 24 from the joint 23, the tool 3 is guided, together with the cutting edge 18 at a preferred small working angle β in a region of between 0° and 20° under an underside of the slug 24. The working angle β is determined here between the longitudinal axis 4 of the tool or the underside 22 of the tool and a component surface 26. The smaller the working angle β is selected to be, the easier is it to lift off or peel off the slug 24 from the component surface 26, that is to say in particular from the base of the joint.

As a consequence of the strong, oscillating impulsive action of the tool 3 along the double arrow 27, which acts substantially parallel to the longitudinal axis 4 of the tool, and thus in a longitudinal direction of the joint 23, lifting off the slug 24 in the direction of the arrow 28 is substantially facilitated such that it is even possible to make long lasting manual use of the device without the risk of the user exhibiting fatigue phenomena.

The wedge face 19 illustrated by the unbroken line is flat. In a deviation here from, the wedge face 19 can also be designed as a concavely curved wedge face 29, as indicated by the dashed line. This facilitates the slug 24, detached from the joint 23, in “running off” or running out from said joint in the direction of the arrow 28 over the tool 3 and away.

FIGS. 4 to 7 show, by way of example, a few alternative joint shapes between connected components of an airplane which can be removed by means of the inventive device.

FIG. 4 shows three components 30, 31, 32 which are connected with the formation of an (butt) joint 33 by connecting elements which are not illustrated. A slug 34 of the sealing material 35 fills the joint 33, preferably completely. The slug 34 of the sealing material 35 and/or the joint 33 have approximately square cross sectional geometry. FIG. 5 shows two overlapping connected components 36, 37, an (overlap) joint 38 being covered by a slug 39 of a sealing material 40. The slug 39 of the sealing material 40 can have a cross sectional geometry of the shape of a quarter-circle or triangle. FIG. 6 shows two components 41, 42 which are overlappingly connected with the formation of a joint 43. A slug 44 of a sealing material 45 runs in the joint 43. FIG. 7 shows two components 46, 47 which are connected to one another at right angles and form a (dummy) joint 48. The joint 48 is filled up with a slug 49 of a sealing material 50. In turn, the slug 49 preferably has a cross sectional geometry of the shape of a triangle or quarter-circle. The joint shapes according to FIGS. 5 and 7 are preferably processed with the aid of a tool 3 which has a rectilinear cutting edge. Particularly in the case of the joint shapes according to FIGS. 4 and 6, it is preferred to use a tool 3 whose processing section 17 has a cross sectional geometry which is adapted to the geometry of the joint cross section.

By comparison with conventional cleaning and/or cutting tools, the joints can be freed or cleared of the sealing material in a substantially shorter time, damage to the component surfaces and serious consequential damage occasioned thereby being largely avoided as a consequence of the softer tool material by comparison with the component material to be processed.

The use of the inventive device thus permits a substantial reduction in time and in the cost caused thereby in the case of the requisite preparatory work for painting fuselage cells and further structural components of airplane. 

1. A device for removing sealing material on components of an aircraft, the device comprising a drive unit and a tool connected to the drive unit, wherein the tool can be caused by the drive unit to execute oscillating movements parallel to a longitudinal axis of the tool in order to facilitate the removal of the sealing material.
 2. The device according to claim 1, wherein the tool has a width which corresponds substantially to a width of a joint between the components.
 3. The device according to claim 1, wherein the tool has a cross-sectional geometry which corresponds substantially to a cross-sectional geometry of a joint.
 4. The device according to claim 1, wherein the tool is made of a material which is softer than the components.
 5. The device according to claim 1, wherein the tool is made of at least one of polycarbonate and hardwood.
 6. The device according to claim 1, wherein the tool has a processing section.
 7. The device according to claim 1, wherein the processing section is substantially a wedge-shaped design, a wedge face enclosing an angle α of between 20° and 60° with an underside of the tool while forming a cutting edge.
 8. The device according to claim 1, wherein the tool can be replaced in a tool holder.
 9. The device according to claim 1, wherein the drive unit is an eccentric driven by an electric motor, a ram which can move in an axial direction being pivoted to the eccentric by an eccentric rod, and the ram being connected to the tool holder.
 10. The device according to claim 1, wherein a speed of the electric motor and/or a stroke travel of the ram can be set in an axial direction by a control and/or regulation device in order to vary an impulsive force of the tool.
 11. The device according to claim 1, wherein the device is a hand-held device.
 12. The device according to claim 11, wherein the weight of the hand-held device is less than 1 kg.
 13. A method for removing sealing material on components of an aircraft, using a device according to claim 1, wherein the underside of the tool is guided inside a joint underneath the sealing material at a working angle β, with respect to a surface of the component.
 14. The method according to claim 13, wherein the working angle β is between 0° and 20°. 